If you have severe thumb pain at the base of your thumb, you may have heard about joint replacement surgery. This article looks at a study that tracked 224 thumb joint replacements over 15 years. The goal was to see what problems happened and which implants worked best.
Here are three things you should know:
- Most thumb joint replacements work well, but some designs have more problems than others.
- The two most common serious problems are the joint popping out of place or the implant loosening.
- The way the surgeon places the implant and the design of the implant both matter a lot for success.
Key Findings at a Glance
- 224 thumb joint replacements were reviewed between 2006 and 2021
- Overall survival rate was excellent, with 97% of implants still working
- Dislocation (joint popping out) happened in 3.5% of cases
- Loosening of the implant happened in 4% of cases
- One implant model (Elektra) was responsible for 47% of all major problems
- Using X-ray guidance during surgery helped place implants more accurately
What Is This Study About?
Doctors in Spain looked back at 224 thumb joint replacements they performed over 15 years. They wanted to understand what serious problems happened with different implant designs. They also wanted to learn how to fix these problems when they occurred.
The researchers studied six different brands of thumb implants. Each brand has a different shape and design. They checked old medical records and X-rays to see how each implant performed over time.
You may be wondering why this matters.
According to this study, knowing which implants work best can help you and your doctor make better choices if you need surgery.
What Is Rhizarthrosis?
Many people with rhizarthrosis first try treatments like splints, medicine, or injections. But when the pain does not go away, some people choose surgery.
One type of surgery is joint replacement. The surgeon removes the damaged joint and puts in an artificial one made of metal or plastic. This is called a trapeziometacarpal prosthesis or TMP.
How Many Implants Were Studied?
Research shows that the doctors looked at 224 thumb joint replacements. They studied six different implant brands. Here is what they found:
| Implant Name | Number of Implants | Survival Rate | Follow Up Years |
|---|---|---|---|
| Arpe | 45 | 95.5% | 6 to 16 |
| Elektra | 5 | 80% | 13 to 14 |
| Ivory | 14 | 92.8% | 9 to 11 |
| Maia | 7 | 100% | 8 to 9 |
| Isis | 115 | 99.1% | 1 to 8 |
| Touch | 38 | 100% | 1 to 4 |
Most of these implants did very well. But the Elektra implant had a lower survival rate of 80%. This means one out of five Elektra implants failed.
What Problems Did Researchers Find?
The study found two main serious problems:
- Dislocation: This means the joint pops out of place. It happened in 3.5% of all implants.
- Loosening: This means the implant becomes loose from the bone. It happened in 4% of all implants.
Here is where it gets interesting.
According to this study, the Elektra implant was responsible for 47% of all major complications. This is surprising because there were only five Elektra implants in the study. But these five caused almost half of all the serious problems.
What Happened When Problems Occurred?
When an implant failed, doctors had to do a second surgery to fix the problem. These are called salvage surgeries. The researchers performed 19 salvage surgeries. In the end, only 3% of all implants were completely lost. This means doctors were able to save most of them.
Which Design Worked Best?
The researchers measured something called the medial angle of the dome. This is a technical way of describing the angle at which the implant sits inside your thumb bone. Think of it like the tilt of a cup on a table. If the tilt is wrong, the cup might tip over.
Let us look closer.
The Isis implant had the smallest angle at 3.8 degrees. The Maia implant had the biggest angle at 14.4 degrees. The other implants were somewhere in between.
The Isis implant was always placed using X-ray guidance during surgery. This is called scopic guidance. It helps the surgeon see exactly where the implant is going. This implant had one of the best survival rates at 99.1%.
Why Does Placement Matter So Much?
Research shows that how the surgeon places the implant is very important. If the implant is tilted too much or sits in the wrong spot, it can pop out or become loose over time.
Using X-ray guidance during surgery helps the surgeon place the implant more accurately. In this study, every Isis implant was placed with X-ray guidance. These implants had fewer problems.
The design of the implant also matters. Some shapes fit better into the thumb bone. Some are more stable. The Elektra design seemed to have more problems than other designs.
What About Long Term Results?
Some implants in this study were followed for up to 16 years. This is a long time. The Arpe implant, for example, had a 95.5% survival rate even after 6 to 16 years. This shows that many thumb joint replacements can last a very long time when placed correctly.
The Touch and Maia implants both had 100% survival rates. But these were followed for shorter periods of time, so we need more years of data to be sure they will last as long.
Common Questions
How common are serious problems with thumb joint replacements?
According to this study, serious problems like dislocation happened in 3.5% of cases and loosening happened in 4% of cases. This means that most thumb joint replacements work well without major issues.
What happens if my thumb implant fails?
If your implant fails, your doctor can perform a salvage surgery. This is a second operation to fix the problem. In this study, doctors were able to save most implants. Only 3% were completely lost and needed a different type of surgery.
Does the brand of implant matter?
Research shows that the brand and design do matter. In this study, the Elektra implant had more problems than other brands. The Isis, Touch, and Maia implants had the best survival rates. Your surgeon can help you choose the best implant for your situation.
Should my surgeon use X-ray guidance during surgery?
According to this study, using X-ray guidance helped surgeons place implants more accurately. The Isis implant was always placed with X-ray guidance and had one of the best results. You can ask your surgeon if they plan to use this technique.
What This Means for You
If you are considering thumb joint replacement surgery, this study gives you helpful information. Most thumb implants work very well. But some designs are better than others. The way your surgeon places the implant is also very important.
Here are some things you can do:
- Ask your surgeon which implant brand they plan to use.
- Ask if they will use X-ray guidance during surgery to help with placement.
- Talk about the risks and benefits of surgery for your specific situation.
- Know that if a problem happens, there are ways to fix it.
Remember that every person is different. What works for one person may not be the best choice for another. Your doctor can help you decide what is right for you.
Disclaimer
This article is for educational purposes only. It is not medical advice. Always talk to your doctor or healthcare provider before making any decisions about your health or treatment. Every person is different, and your doctor can give you advice based on your specific situation.
Study Reference
Sanchez-Crespo, M. R.; Couceiro-Otero, J.; Del Canto-Alvarez, F. J.; Ayala-Gutierrez, H.; Holgado-Fernandez, M. (2024). Experience in major complications with total trapezometacarpal prostheses. Rev Esp Cir Ortop Traumatol.